Left picture: The diagnosis is a cystic lymphangioma.
Right picture: Here, the diagnosis is a chronic lymphadenitis following a BCG vaccination.

In both toddlers there is a swelling of the chest wall close to the left axilla.
Left picture: This pathology became gradually larger after birth, and is smooth and cystic on palpation.
Right picture: In this toddler the skin over the pathology is reddened, and a firm mass is palpable which is fluctuating here and there; the history reveals a BCG vaccination on the left upper arm.